standard thermodynamic quantities

https://doi.org/10.1351/goldbook.S05927
Values of thermodynamic functions in the @[email protected] characterized by a @[email protected], molality or @[email protected], but not by temperature. Standard quantities are denoted by adding the superscript \(^{\text{⦵}}\) or \(^{\unicode{x26ac}}\) to the symbol of the quantity.
Source:
Green Book, 2nd ed., p. 53 [Terms] [Book]
See also:
PAC, 1994, 66, 533. (Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)) on page 536 [Terms] [Paper]